Switching and signaling mechanism



Dec. 8, 1936. A. K. ANDRIANO SWITCHING AND SIGNALING MECHANISM Filed June 10, 1955 3 Sheets-Sheet 1 0/ m m w WA K m E 8 L A A TTORNEYS.

Dec. 8, 1936. ANDRIANO 2,063,009

SWITCHING AND SIGNALING MECHANISM Filed June 10, 1935 3 Sheets-Sheet 2 IN V EN TOR. ALBERT A ocH ANDR/ANO,

M, M 1 ATTORNEYS.

Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE 28 Claims.

This invention relates to intercommunicating systems, as between telephones or other instruments, and with respect to its more specific features to switching indicating and control mechanism in conjunction with such systems.

The invention also relates to improvements in dials or indicators and in signaling and switching devices and circuit controlling means for electrical signaling and power units and for telephone systems of the kind in which each telephone or station is provided with means for ob taining direct communication with another station without a central exchange.

One of the objects of this invention is the provision of a switching and signaling mechanism which can be quickly and simply operated and which practically eliminates all danger of erroneous operation.

Another object is the provision, in a device of the above character, of a dial or plate having a point of rest, or station, indicated thereon by characters or numerals soarranged that they can be read in any direction.

The invention also has for its object a novel construction of switching and connecting means and signaling devices for telephones of this character; to provide a dial that when rotated in either direction (to right or left) at all times shows the numbers, letters or other designations on the dial in readable (upright) position; to simplify and combine the operation of the switching and signaling device so that connection is made with any selected circuit or station and the selected station or unit is signaled with one rotary motion.

' A further object is the provision in a telephone system of a practical switch for use with a telephone station which may be used in connecting that station with any other station in the system and which may be left in any position upon the completion of the call without preventing that station from receiving calls from other stations.

Another object is to provide a satisfactory rotary switch which may be employed in many different associations and which may be selectably operated to close any one of a plurality of switches without danger of confusion on the part of the operator.

A further object is the provision of a stop for a shiftable switch which serves to restrain further shifting of said switch and which will serve further as a circuit closer.

Among other objects is the provision of a novel signaling and switching mechanism for a telephone system, the operation of which may not be completed until the receiver is removed from the hook, which has figures or dial numbers that are always in readable position, and which has a signaling key which serves as a stop member for the dial and is a circuit closer to complete the circuit between the telephone stations.

A further object is to provide a compact unitary dialing mechanism which may readily be attached to any telephone base, parts of which are individually rugged, which may be economically constructed, and which will operate over long periods of time with freedom from repairs.

Further objects will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation, partly in section, of a desk telephone and a switching and signaling device attached thereto, both embodying certain features of the present invention;

Fig. 2 is a plan view, partially fragmentary, of a dialing mechanism such as is employed on the base of the telephone in Fig. 1, showing the finger plate, screen, dial plate, ratchet, and signaling key;

Fig. 3 is a side elevation of a portion of a telephone, with the casing broken away showing the receiver hook in depressed position as when the receiver is on the hook and showing also a novel switch and latch arrangement embodying certain features of the present invention;

Fig. 4 is a side elevation in detail of the lower portion of the mechanism disclosed in Fig. 3, showing the novel latch arrangement which operates in response to the receiver hook;

Fig. 5 is a side elevation similar to Fig. 3, showing the receiver hook in elevated position as when the receiver is removed.

Fig. 6 is a plan view of a portion of a dial switch and telephone base taken along the line 6--6 of Fig. 1, and showing in detail the signaling key;

Fig. '7 is a plan view of the contact base and switching mechanism controlled by the dial;

Fig. 8 is a plan view of the dial plate, screen,

and finger hole plate, with portions partially broken away so as to reveal the novel arrangement of the numbers on the dial and the construction of the screen;

Fig. 9 is a plan view of a modified form of dial plate, screen, and finger hole plate, embodying certain features of the present invention, showing the numbers, screen, and finger hole plate arranged in a different manners Fig. 10 is a plan View of another form of dial plate, screen, and finger hole plate, embodying features of the present invention;

Fig. 11 is a diagrammatic representation of a telephone system of the direct line type, showing a novel switching and signaling mechanism embodying features of the present invention; and

Fig. 12 is a diagrammatic representation of a signaling system or circuit, embodying features of the present invention.

Referring now more specifically to Figures 1 through 5, the numeral indicates a telephone, and 2 indicates generally a dial switch, both of which embody certain of the features of the present invention. The telephone illustrated is of the type generally known as a desk set, and comprises transmitter or mouthpiece 4, base 3, and the upright connecting portion 5. A plate 1 extends through the upright portion and is secured in position by suitable fastening means such as rivet 41. -A screw 6 secured to the plate retains the bottom of the telephone in position. The plate 1 is formed with an opening 29 and pivoted at this point and extending through the opening and through the outer casing of the telephone is a receiver hook such as lever or arm 8, which is preferably formed at its outer end with a bifurcated hook (not shown) for retaining a telephone receiver. This may be of the conventional type usually employed on a telephone desk set. At the opposite end of the member 8 is an extension 9 which is preferably formed with a protrusion l0 formed of insulating material for engaging the switch mechanism-which will be described later. A rod extends along the inside of the casing of the telephone from the member 8 into the base portion. The rod is supported so as to permit of longitudinal shift movement. This may be accomplished by having the rod loosely supported by two posts, shown at l2 and I3, secured to the plate 1 and to the side or casing of the telephone. A spring l4 normally'forces the rod ll upward so as to press the receiver hook 8 upwardly and retain it in the position shown in Figure 5. However, when the receiver is placed upon the hook, the weight thereof is sufficient to counteract the pressure of the spring and to force the lever 8 and the rod I downward into the position shown in Figure 3. Secured to the lower end of the plate 1 is a member l5 which serves as a supporting plate for the latch mechanism about to be described. The member I5 is formed with a horizontal base Hi to which is fastened a plate l1. The plate I1 is formed with two extensions or legs l1 and I1". Pivoted between the lobes or cars I8 formed on the two extensions or legs of the member I1 is the latch mechanism I9. The latch mechanism has three separate parts, a rearwardly extending lever 20, the latch piece 2| and a dog 22. The lever 20 extends rearwardly into the path of movement of the rod II and when the receiver is upon the hook 8 the rod II is pressed downwardly and engages the lever 20, causing the members 2| and 22 to assume the positions shown n Figure 3. Extending between the dog member 22 and the extension 23 on the bottom of plate I5 is a spring 24. It will be seen that when the receiver is removed from the hook, spring I4 will push the rod into elevated position. The end of rod II will move out of engagement with the lever 20 and spring 24 will cause the member 22 and 2| to assume the position shown in Figure 4. The dog member 22 is so formed that when the receiver is on the hook it extends above the surface of the plate |1 so as to serve as a block or stop to resist any lateral movement of the member 14. The latch member 2| is preferably longer than the dog 22 so that when the receiver is removed from the hook it will normally rest upon the member 14, as shown in Figure 4.

Fastened to the middle portion of plate 1 is the block 25, having three contact springs 26, 21 and 28 mounted thereon. The springs are so arranged that contact 21 is normally in engagement with contact 28, and out of engagement with contact 26, as shown in Figure 5. How- -ever, the contact spring 21 is formed with an extension which is engaged by the protrusion l0 formed on the end of the receiver hook 8. When the receiver is on its hook, the extension on member 21 will be engaged by the protrusion l0 and contact 21 will be forced out of engagement with the contact 28 and into engagement with the contact 26, as shown in Figure 3. When the receiver is removed from the hook, however, the pressure upon the spring 21 by the protrusion ID will cease, and the contacts will again return to their normal positions, as shown in Figure 5.

The latch mechanism and switch mechanism heretofore described are illustrated in the accompanying drawings in association with a telephone of the type commonly known as a desk set. However, it is to be understood that it is within the purview of this invention to employ a latch mechanism and switch mechanism of this type in any type of telephone, such as a French telephone or a wall telephone. In each instance the mechanisms will operate in response to depression and release of the receiver holder. The novel dialing or rotary switch mechanism is disclosed at 2 in Fig. 1 and in detail in Fig. 2 and in Figs. 6 through 10. While the mechanism hereinafter described is illustrated in association with a telephone, and while it is especially suited for use in a telephone system, it is nevertheless within the purview of certain aspects of the present invention to employ such a switch in other types of electrical circuits such as the signaling system illustrated in Fig. 12.

The dialing mechanism is preferably formed with a central pivot 30. On the bottom of the pivot is an adjustable collar 3| which may be held in place by a set screw 32. The top of the pivot is preferably formed with a threaded opening into which is introduced the screw 33. It is preferred that certain portions of the pivot be circular in cross section so members may be rotatably mounted thereon and that other portions be irregular or rectangular in cross-section so that members may conveniently be fixedly mounted thereon. Fixedly mounted on the pivot is the dial plate 34. This is preferably formed with an opening at its center, generally rectangular in shape so as to cooperate with a. rectangular portion of the central pivot member. Because of this construction, rotation of the pivot member will cause rotation of the dial member. On the dial plate are symbols as the numerals indicated by 60, each indicating a diiferent station or point of rest of the switch, or, in the case of a telephone system, each numeral representing a telephone station in the system. These numerals are so arranged that a numeral for each station of the switch will always be in readable position.

In Fig. 2 and Fig. 8 of the accompanying drawings, this is accomplished by placing two concentric rows of figures on the dial plate so as to form a plurality of pairs of figures. That is, there aretwo number ones, one disposed nearer the edge than the other. number twos, threes, etc., disposed in similar relation. In this modification each point of rest of the switch, or each station in a telephone system, will be represented by a pair of the same number. In Figs. 2 and 8 the inner row is in upright position from the edge of the dial, while the outer row is in upright position from the center of the dial. It will be seen that on the lower half of the dial, the inner row of figures appears in readable position, while on the upper half of the dial the outer row of figures appears in readable position. If the dial is rotated, it will be seen that the figures on the top portion of the dial in readable position become in nonreadable position as they enter the lower half of the path of rotation and those in non-readable position become in readable position. Likewise, the position of the figures on the lower portion of the dial is reversed as they are rotated to the top portion.

In Fig. 9, the numerals or characters on plate 34 are arranged generally as in Figs. 2 and 8. However, the inner row of figures is spaced at a greater distance from the outer row so that the figures of each pair will be farther apart. This arrangement will permit of a variation of the structure of the screen and finger hole plate, which will be described later.

In Fig. 10, the figures are illustrated as appearing in pairs. The pairs of figures, however, instead of forming two concentric rows as in the previous illustration, are arranged so that two of the same figures are placed side by side. One figure in each pair is disposed in inverted re-. lation to the other figure of the pair. It will be seen that as the dial is rotated, one of the figures of each pair will always be in readable position. The figure in readable position at the top of the dial will be in non-readable position as it is rotated to the bottom. Likewise, the figure in non-readable position at the top will be in readable position when rotated to the bottom. In the modifications illustrated in the accompanying drawings, each station is indicated by a pair of numbers, one in inverted relation to the other. Upon rotation of the dial, there will always be one figure in each pair in readable position. At no time will both figures in a pair be inverted below horizontal position.

Of course it is to be understood that many variations may be made in the arrangement of the characters or numbers on the dial without departing from the present invention. Instead of using a pair of figures'as shown in the accompanying drawings, a plurality of figures such as three or four may be employed, eachreadable in different directions. It is to be understood also that while the accompanying drawings show numbers on the dial plate, other symbols or characters, such for example as letters, may be employed.

It is within the purview of certain aspects of this invention that the dial plate herein de- Likewise, there are twoplate 34.

scribed may be used alone and not in association with the screen and finger hole plate described hereinaiter'. When used alone, it will be seen that a character or number representing each of the points of rest or stations of the dial acters in readable position. Solid shielding portions 31 are disposed so as to conceal the characters not in readable position. The screen is fixedly mounted so that it may not rotate with the pivot 30 or the dial 34. This may be accomplished by forming the shielding portions out of an integral sheet of metal with three extensions 38 fastened by means of screws 39 to plate 55, which in turn is made fast to the base of the telephone as hereinafter described. To secure additional support the screen may be formed with a central portion loosely engaging the central pivot, but not fixedly mounted thereon.

In the modifications illustrated in Figs. 2, 8 and 9, the screen is formed so that the openings reveal the outer row of figures on the top row of the dial and the inner row of figures on the bottom portion of the dial and the shielding portion covers the inner row of figures on the top portion of the dial and the outer row of figures on the lower portion of the dial. In the-modification shown in Fig. 10, the openings 36 are preferably in the form of a semi-circle, the openings at the upper portion of the screen being complementary to the openings on the lower portion of the screen.

In all of the modifications illustrated the screen is stationary. The screen is so formed that solid shielding portions will conceal the symbols or numbers in non-readable position during every portion of the shift path of the dial and will reveal the numbers in readable position in every portion of the shift path. It will be seen nowthat as the dial is rotated from station to station, the figures exposed to view will always be in readable position. Those in non-readable position will be concealed by the shielding portions 31 of the screen 35.

Disposed above the screen and fixedly mounted on the pivot 30 is the dial operator or finger hole plate 40. Rotation of the finger hole plate will cause rotation of the pivot and of the dial The finger hole plate is formed with a series of openings or orifices arranged so that each opening appears above a character on the dial member. In the modifications shown in Figs. 2, 8 and 10, a pair of the same figures appear under each opening. However, the screen serves to conceal the figure in each pair not in readable position. In the modification illustrated in Fig. 9, in addition to the openings 4|, the finger hole plate is formed with windows or openings 42. On the upper portion of the dial the figures in normal reading position are seen through the finger hole openings 4| and on the lower portion of the dial the figures are seen through the windows 42.

To operate the mechanism heretofore described a finger is inserted in the finger hole appearing above the number of the desired station and the plate is rotated until the finger engages the stop 12. Rotation of the finger hole plate causes rotation of the pivot and of the dial plate. For

instance, if the operator wishes to make connection with station number eight of a telephone system, he inserts his fingerin the hole of the plate 40 appearing above the number 8 and rotates the plate until his finger engages the stop 12. It will be seen that during all stages of the operation, there will always be a number in readable position for each station.

Loosely mounted on the bottom of the pivot 30 is the contact support 45. This is formed of an insulating material and ispreferably fixed at three points 46, by means of screws 4| passing through spacers 40, to the base of the telephone so that it cannot rotate with the pivot. Mounted on the contact base are a series of contact points 48, 48", 48", etc., and when used in a telephone system as shown in Fig. 11, each one of these contact points is connected to the circuit of a telephone station, or, when used in a signaling system, as in Fig. 12, to a signaling circuit, as will be later described. A circular contact 49 is also fixed to the contact base. Immediately above the contact base is a switch bar or contact arm 50. This is fixedly mounted to the central pivot 30 by means of a suitable fastener such as set screw 5|. One end of the contact strip indicated at 52, is preferably arranged so as to-continuously engage the circular contact 49 and the other end indicated by the number 53 is arranged so as to successively engage the contact points 48', 48",

48" as the switch bar is rotated.

It will be seen that if the finger hole plate is rotated as described above, the pivot will be rotated and consequently the dial and the switch bar 50. This will cause the switch bar to successively engage the contacts 48', 48", etc. It is preferred that the dial member should have a numeral or symbol to represent each of the contacts 48',.48", etc. The numbers are so arranged on the dial that when the number is adjacent the stop key I2, the switch arm is in engagement with the contact point represented by the number 48'. If the operator should desire to close the circuit between the contact 49 and the contact point 48", all that he has to do is to insert his finger in the finger hole appearing above the number 2 and rotate the finger hole plate until his finger engages the stop key I2. The circuit will then be closed. Because of the novel arrangement of the numbers and because of the construction of the screen, a number representing each of the stations or contacts will always be in readable position. When the finger hole plate is rotated so that the dial numbers appear in difierent relative positions, they will nevertheless always appear to the operator in readable position. This serves to eliminate confusion and errors which normally would result therefrom.

Turning again to the construction of the dial switch, the numerals 55 and 56 represent two plates with central apertures loosely engaging pivot 30. They are held against rotation with the pivot by being fixedly mounted on the telephone base at points 65 by means of screws 44 and 56 which are threaded into spacer members 43 and 51 respectively. It will be observed that the screws 44 pass directly through portions 68 of the telephone base and serve to firmly hold the spacer members 61 and 43 thereto. The plates 55 and 56 serve to support the central pivot, and

' as a mounting for several stationary parts such as the screen, pawl and spring.

If desired, a ratchet wheel Il may be secured to the undersurface of the dial plate 34 or may be fixedly mounted on the pivot 30 in order to prevent the dial switch from rotatingin both directions. If the ratchet is employed, a pawl 69 pressed by the spring I may be mounted on the fixed plate 56 so as to engage the teeth of the ratchet wheel II as illustrated in Fig. 2. Under this construction the dial switch may only be operated in a clockwise direction, the pawl and.

ratchet serving to prevent counterclockwise rotation.

A stop, or signaling key I2 is provided immediately above the finger hole plate, and as previously described, serves to engage the finger and stop further rotation when the contact to the selected station has been closed. When used in a telephone system, it may serve also as a signaling key to ring the bell of the selected station. To accomplish this it has an arm I3 formed with an aperture loosely encircling the central pivot 30 so as not to rotate therewith. At its opposite end it is formed with an extension 14 previously referred to which projects into the telephone base and normally rests adjacent the latch mechanism in the telephone base. Disposed between the latch mechanism and the central pivot 30 and adjacent to the arm I3 is a contact blockfI5. This contact block I5 is preferably formed of a plurality of contact strips I6, II, I8, I9, 80 and 8|, fastened together by a series of insulating blocks I5 which in turn are mounted on the contact base 45. The

strips are so formed that normally contact strip I1 is out of engagement with contact strip I6 and in engagement with contact strip I8, and contact strip 80 is normally in engagement with contact strip I9 and out of engagement with contact strip 8|. However, contact strips 11 and 80 are formed with extensions II and 80' which are in position to be engaged by the arm I3 if pressure is exerted on the key I2 to shift that arm. The arm I3 is suitably insulated where it comes in contact with extensions 11' and 80'.

Dog 22 of the latch mechanism, previously described, serves to restrain shifting of the arm I3 when the receiver hook of the telephone is depressed. When the receiver hook is depressed, the dog 22 is in the position shown in Fig. 3 and if pressure is exerted upon the key 12 the arm I3 will be restrained from shifting because the dog 22 engages extension I4. When the receiver is removed from the hook, the spring 24 will remove dog 22 from the path of movement of arm I3, as shown in Fig. 4. If pressure is then exerted on the key I2, the arm I3 will shift inwardly into engagement with the contact strip extensions 11' and 80', forcing the contact I1 out of engagement withcontact 18 and into engagement with con tact I6 and forcing contact 80 out of engagement with contact I9 and into engagement with contact 8|.

A coiled spring 85 anchored to the stationary plate 55 engages the arm I3, serving to return the arm I3 and key I2 to their normal position when pressure is released upon the key I2. However, the latch piece 2| will prevent 'the arm I3 from fully returning to its normal position. It will engage the extension I4 and retain it in the position indicated in Fig. 5. The contact strip extension 11' is preferably shorter than the contact strip extension 8|!v and the latch 2| is long enough to permit the arm I3 to be shifted by the spring 85 so that it will no longer be in engagement with extension II, but will still be in engagement with 80'. Contact 11 will then return to its normal position, that is, out of engagement with contact I6 and in engagement with contact I8. Contact 80 will remain in engagement with contact 8| and out of engagement with contact 19.

When the receiver hook 8 is depressed, as when the receiver is returned to the hook, the latch 2| will be elevated, due to the pressure on lever 20 by rod II, and the parts will again return to the position illustrated in Fig. 3. The arm I3 will then be out of engagement with the extension and contact 80 will again engage contact I9 and be free from engagement with contact 8|.

In order to more thoroughly understand the,

operation of the novel latching, switching and dialing mechanism heretofore described, reference may be had to Figure 11, which shows an embodiment of the present invention in association with a telephone system.

Figure 11 is a diagrammatic representation of a telephone system of the direct line type, i. e., communication between the stations of that system is not made through a central exchange, but is made directly between the stations. The system disclosed has two stations, indicated gen erally as station I and station II. A suitable source of current supply for the talking circuit such as battery 80 is connected, by means of line 8| to common return line 82 and thence to the,

transmitter I30 of station I, and to the transmitter I3I of station II. The line 84 connects the source of current supply to impedance coils 85 and 86, which are connected by lines 81 and 88, respectively, to lines 89 and 90. Line 89 is connected to the contact strip I9 of station I, and line 90 is connected to contact strip I9 of station III. The contact strip 21 of station I is connected by means of line 9| to contact 18; likewise, contact strip 21 of station II is connected by means of wire 92 to contact strip I8 of that station. Contact strip 28 of station I is connect-' ed by means of wire 93 to the primary of induction coil I35 and then to the transmitter, and the contact strip 28 of station II is connected by means of wire 94 to the primary of induction coil I36 which in turn is connected to the transmitter of that station. Contact strip 8| of station I is connected to a circular contact 49 by means of a line 95, and contact strip 8| of station II is connected by means of wire 98 to circular contact 49 of that station. The contact point 48" of station I is connected by means of wire 91 to the line 90 leading to contact strip I9 of station II. Contact point 48' of station II is connected by means of wire 98 to line 89, which leads to contact strip I9 of station I.

Another source of current supply such as battery 99 serves to energize the signaling mechanisms of the stations which consist, in the present case, of the bells I00 and IOI. Line I02 connects one terminal of the battery to lines I03 and I04, which supply one post of the signaling bells I00 and I0 I Another line I 05 connects the other side of the current supply to lines I06 and. I01. Line I06 is connected to the contact strip I6 of station I and line I01 is connected to the contact strip I6 of station II.

Each station of the telephone system has the novel latching arrangement I9, switch block 25, dialing mechanism 2, signaling key I2, switch mechanism I5, all of which has been described heretofore. The telephone system disclosed in.

Figure 11 is operated as followsz-A station desiring to call another station must first remove the receiver from the hook so that the receiver hook 8-assumes an elevated position. In Figure 11 the receiver of station I has been removed from the hook. If the operator of station I desires to call station II, he inserts his finger in the hole of the finger hole plate appearing above the numeral 2 and revolves the plate until his finger is engaged by the stop or signaling key I2. The

switch bar 50 is then connected between circular contact 49 and the contact 48" as in Figure 11 at station I. Pressure is then exerted on the member I2 in the direction of rotation or the dial, that is, in a clockwise direction. Because the receiver is off the hook, the rod II is in elevated position and the stop 22 is not in the path of movement of extension I4 of arm I3. The arm I3 will thereafter shift in response to pressure on the key I2 into contact with the contact strip extensions 11' and 80', causing contact strip 11 to move out of engagement with contact strip I8 and into engagement with contact strip I6, and the contact strip 80 out of engagement with the contact strip I9 and into engagement with the contact strip 8|. This will cause the current from battery 99 to flow through wires I05, I 06, contact strips 16, 11, wire IIO, contact strip 80 through contact strip 8|, through wire to circular contact 49; through switch bar 50 to contact 48"; and by means of wires 91 and 90 to contact strip I9 of station II. Contact strip I9 is in engagement with contact strip 80 and accordingly the current will pass through contact strip 80, wire III, contact strip 11, contact strip I8, wire 92, contact strip 21, contact strip 26, wire 3 to one post of the signaling bell IN and thence through wires I04 and I 02 back to the battery 99, thereby completing the circuit to the signaling bell of station 11. Figure 11 portrays the stations during this state of the operation. The'receiver of station I has been removed from the hook, the dial has been rotated to select station II, and pressure has been exerted on stop key or signaling key 12 to ring the bell of station II. When station II responds to the ringing of its bell and removes its receiver from the hook 8, the contact strip 21 will move out of engagement with the contact strip 26 and into engagement with contact 28, thereby breaking the circuit to the signaling bell I0|, which will accordingly stop ringing.

After ringing the bell, the operator of station I will release pressure upon the stop I2, then arm I3 will be moved by means of circular spring 85 so that it will be out of engagement with contact strip extension 11. However, the latch 2| will retain the member I4 so that arm I3 will remain in engagement with the contact strip extension 80'. Contact strip II will then be in engagement with contact strip I8, but out of engagement with contact strip 16, and the circuit of the signaling bell of station II will thus be broken in a second place. Contact strip 80 will remain in engagement with contact strip 8| and out of engagement with contact strip I9. The talking circuit between the two stations will now be completed. Transmitter oi station I is connected through the primary circuit of induction coil I35 to wire 93, contact strip 28, contact strip 27, wire 9|, contact strip I8, contact strip II, wire 0, contact strip 80, contact strip 8|, wire 95, circular contact 49, switch bar 50, contact 48", wires 91 and 90, contact strips I9 and 80 of station II, wire II, contact strip 11 and I8, wire 92,

contact strips 21 and 28, and wire 94 to the pri-,

mary circuit of induction coil I36 to the transmitter of station II, and thence by means of common return wire 82 back to the transmitter of station I.

As previously stated, the battery 80 is connected by means of wire 8| to the common return wire 82 and by means of wire 84 to the impedance coils 85 and 86, which in turn are connected by the wires 81 and 88 to lines 88 and 88. The talking circuit between the two stations has therefore been completed. When the conversation between the two stations has been completed, the receivers are replaced upon the hooks 8 which will accordingly be depressed. At station II contact strip 21 will be forced out of engagement with contact strip 28 and into engagement with contact strip 26. Station 11 will once again be in condition to receive any incoming calls. At station I, when the receiver hook 8 is depressed, contact strip- 21 will likewise be forced out of contact with contact strip 28 and into engagement with contact strip 26. The rod II will also be depressed, forcing the lever 28 downwardly. The latch 2| will accordingly be raised and spring 85 will return the arm I3 to its normal position which is indicated at station II. Contact strip 80 will accordingly be released by the arm 13 and will move out of engagement with contact strip 8I and into engagement with contact strip 19. Station I will now be in condition to receive anyincoming calls. Any station may call another station by following the procedure outlined above. While in Fig. 11 but two stations are illustrated in the system, it is to be un derstood that any number of stations may be employed. The rotary or dial switching mechanism 2 will have a contact point 48 for each of the other stations in the system. The contact point for each station will be connected to the direct line of that station.

It will be observed that in the present circuit it is immaterial what position the dial switch is left in upon .completing a call. In other words, after conversation between two stations has been completed, it is not necessary to return the dialing switch to any particular position in order to receive an incoming call. This is true because incoming calls are not received through the dial switch 2, but are received by a direct line, in the case of station I, line 89, and in the case of station II, line 90, each connected to its respective station through switch blocks 15. Outgoing calls, however, are made through the dialing switch, each station in the system will have a contact 48 etc., connected to the direct line of the other stations of the system, and by rotating the dial switch, connection can be made to the direct line of any other station in the system.

Figure 12 is a diagrammatic representation of a signaling system employing a novel dialing or rotary switching mechanism embodying certain aspects of the present invention. One of the terminals of a source of current supply, such as battery H5, is connected by means of wires HI and I22 to one post of a signaling bell I26 and by means of wires I2I and I23 to a post of signaling light I21. The other post of signaling bell I26 is connected by means of wire I24 to contact point 48'. The other post of the signaling light is connected by means of wire I25 to contact point 48". The circular contact 49 is connected by means of wire I20 to contact strip H8. Con tact strip II! is connected by wire 6 to the other terminal of battery H5. The mechanism is operated as follows:-If the operator wishes to ring the bell I26, he inserts his finger in the finger hole above the symbol on the dial plate representing that bell. For purposes of illustration we will say that I indicates the signaling bell and 2 the light. He will then rotate the finger hole plate in a clockwise direction until his finger engages the stop 12. The switch bar 50 will then be in the position shown in Fig. 12, i. e., connected described. Of course, any number of signaling a circuits may be employed.

It will be seen from the above illustrations that the novel switching and dialing mechanism may be used in association with many different types of circuits such as signaling, communicating, or power circuits.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent 1. A dial for a rotary switch comprising, in combination, a member mounted for rotary shift movement, and symbols on said member to indicate the various stations of said switch, said symbols being arranged so that a symbol for each station is always in readable position for each station position of the dial.

2. A dial for a rotary switch comprising, in combination, a member mounted for rotary shift movement, and symbols on said member to indicate the various stations of said switch, each of said stations being represented by a plurality of the same symbol each readable in a different direction.

3. A dial for a'rotary switch comprising, in combination, a member mounted for rotary shift movement, and a plurality of symbols on said member to indicate one station of said switch,

each of said symbols being readable in a different direction.

4. A device of the character described comprising, a member shiftable from station to station, and a plurality of numbers on said member indicating the same station, each of said numbers being readable in a different direction.

5. A device of the character described comprising a member shiftable from station to station having two like numbers indicating the same station, one .of said numbers being arranged in inverted relation to the other, and means cooperable to display one of said numbers in readable position when the other is in non-readable position.

6. A device of the character described com. prising a member shiftable from station to station having two like numbers indicating the same bers in readable position at another point in the shift path of said dial.

8. A device of the character described comprising, in combination, a member rotatably shiftable from station to station, and two like numbers on said dial indicating the same station, one of said numbers being arranged in inverted relation to the other.

9. A device of the character described comprising, in combination, a member rotatably shiftable from station to station, two like numbers on said dial indicating the same station, one of said numbers being arranged in inverted relation to the other so that upon shifting of said dial one num-v ber will change from readable to non-readable position and the other from non-readable to readable position, and means cooperable to screen from view the number in non-readable position.

10. A device of the character described comprising, in combination, a number dial rotatably shiftable from station to station, and a lightscreen disposed adjacent said dial.

11. A device of the character described comprising, in combination, a dial rotatably shiftable from station to station, and ascreen disposed adjacent said dial, said dial having two concentric series of station numbers and said screen being cooperable at one part of the dial to cover numbers of one of said series while permitting view of the numbers of the other series at said part and at another part of the dial to cover numbers of the last mentioned series while permitting view of numbers of the other series at said other part.

12. A device of the character described comprising, in combination, a dial rotatably shiftable from station to station, a screen disposed adjacent said dial, said dial having two concentric series of station numbers and said screen being cooperable at one part of the dial to cover numbers of one of said series while permitting view of the numbers of the other series at said part and at another part of the dial to cover numbers of the last mentioned series while permitting view of numbers of the other series at said other part, and a finger hole plate rotatably shiftable with said dial.

13. A device of the character described comprising, in combination, a number dial mounted, for rotary shift movement, a finger hole plate cooperable to cause rotary shift of said dial, and a stationary screen interposed between said finger hole plate and said dial and cooperable to conceal some of the numbers thereon.

14. A device of the character described comprising, in combination, a dial member mounted for rotary shift, a finger plate having a plurality of finger holes cooperable to cause rotation of said dial member, and a pair of numerals disposed on said dial member beneath each of said finger holes, both of the numerals in any one pair being the same but in inverted relation to each other.

15. A dial switch for use in a telephone system having a plurality of stations comprising, in combination, a rotatably shiftable member, means acting in response to shifting of said member for connecting one station to another station, and symbols on said member to indicate points of connection with different stations, said symbols being arranged so that a symbol for each station is always in readable position.

16. A dial switch for use in a telephone system having a plurality of stations comprising, in combination, a rotatably shiftable member for connecting one station to another, symbols on said member to indicate the point of connection with each of said stations, each of said points of connection being represented by a plurality of the same symbol each readable in a difierent direction, and means for concealing those symbols for each point not in readable position.

17 A dial switch for use in a telephone system having a plurality of stations comprising, in combination, a rotatably shiftable member for connecting one station to another, symbols on said member to indicate the point of connection with each of said stations, each of said points of connection being represented by a pair of the same symbols, one readable in one direction and the other readable in another direction, and means for concealing the symbols readable in one direction on one segment of said member and for concealing the symbols readable in the other direction on the remaining segment of said member.

18. A dial switch for use in a telephone system having a plurality of stations comprising, in combination, a rotatably shiftable member, means responsive to shifting of said member-to connect one station with any one of the other stations, a plurality of pairs of visible symbols on said shiftable member, each pair indicating a point of connection with a different station, one symbol of each pair being disposed nearer the center of said member and being in readable position from the edge thereof, and the other symbol of each pair being disposed nearer the edge of said member and being readable from the center thereof, and means comprising a stationary screen cooperable to conceal the symbols disposed nearer the center of said member on one portion thereof and for concealing the symbols disposed nearer the edge on the remaining portion of said member so that a symbol for each station will always be in readable position.

19. A device of the character described comprising, in combination, a shiftable switch member, a circuit closer, and means disposed in the path of movement of said switch member cooperable to operate said circuit closer upon shifting of said switch member.

20. A device of the character described for use with the station in a telephone system having a plurality of stations each with a Signaling bell comprising, in combination, a finger operated switch member for connecting said first mentioned station with another station, a stop for engaging the finger when the switch has been operated to connect said two stations, and means cooperable upon the application of pressure to said stop in the direction of movement of said switch to ring the bell of said last mentioned station.

21. A device of the character described for use with the station in a telephone system having a plurality of stations each with a signaling bell comprising, in combination, a finger operated switch member for connecting said first men'- tioned station with another station, a stop for engaging the finger when the switch has been operated to connect said two stations, means cooperable upon the application of pressure to said stop in the direction of movement of said switch to ring the bell of said last mentioned station, and means operable upon releasing the pressure on said stop to close the circuit between said stations.

22. A device of the character described for use with the station in a telephone system having a plurality of stations each with a signaling bell comprising, in combination, a finger operated rotary dial switch for connecting said first mentioned station with another station, means comprising a pawl and ratchet cooperable to prevent rotation of said switch in one direction, a stop for engaging the finger when the switch has been operated to connect said two stations, and means cooperable upon the application of pressure to said stop in the direction of movement of said switch to ring the bell of said last mentioned station.

23. A device of the character described comprising, in combination, a shaft, a finger plate, a number plate, and a screen positioned intermediate said finger plate and said number plate, said finger plate and number plate being mounted on said shaft so that rotation of the finger plate will cause rotation of the number plate.

24. A device of the character described comprising, in combination, a shaft, a finger plate and a number plate disposed around said shaft so as to rotate therewith, a screen loosely mounted on said shaft and interposed between said finger plate and number plate, and means cooperable to prevent said screen from rotating with said shaft.

25. A dial switch for a telephone system having a plurality of stations comprising, in combination, a shaft, a finger plate for rotating said shaft, a dial member mounted on said shaft to rotate therewith, a plurality of numbers on said dial indicating each of the stations, and a screen interposed between said finger plate and number plate so as to conceal some of the numbers.

26. A dial switch for a telephone system having a plurality of stations comprising, in combination, a shaft, a finger plate for rotating said shaft, a dial member mounted on said shaft to rotate therewith, two numbers on said dial indicating one of said stations, one being in readable position and one in non-readable position, and a screen disposed around'said shaft and fixed against rotation therewith for concealing the number in inverted position.

27. A dial switch for use in a telephone system having a plurality of stations comprising, in combination, a central pivot, a finger 'hole plate mounted on said pivot and cooperable to cause rotation thereof, a dial member fixedly mounted on said pivot so that rotation of the pivot will cause rotation of the dial member, a contact base loosely encircling saidpivot and fixed against rotation therewith, a plurality of contact points each having connection with a station of the telephone system mounted on said contact base, a contact arm fixedly mounted on said pivot and cooperable to successively engage said contact points upon rotation of said pivot, a plurality of pairs of numerals on said dial member each pair indicating a station, one numeral of each pair being in inverted relation to the other numeral of that pair, and means comprising a screen disposed around said pivot and fixed against rotation therewith for concealing the numerals not in normal reading position.

28. A dial switch for use in a telephone system having a plurality of stations comprising, in combination, a central pivot, a finger hole plate mounted on said pivot and cooperable to cause rotation thereof, a dial member fixedly mounted on said pivot so that rotation of the pivot will cause rotation of the dial member, a contact base loosely encircling said pivot and fixed against rotation therewith, a plurality of contact points each having connection with a station of the telephone system mounted on said contact base, a contact arm fixedly mounted on said pivot and cooperable to successively engage said contact points upon rotation of said pivot, a plurality of pairs of numerals on said dial member each pair indicating a station, one numeral of each pair being in inverted relation to the other numeral of that pair, means comprising a screen disposed around said pivot and fixed against rotation therewith for concealing the numerals not in normal reading position, and a signaling key loosely mounted on said shaft and oscillatable in line with movement of said dial, said key having a member extending into the path of movement of the operators finger.

ALBERT KOCH ANDRIANO 

